Reliability Analysis Of Polymer Composites Considering The Degradation Of Strength

The advanced composites have many unique properties, with their widely using for aerospace and aircraft applications, researching the secure problems of composites structure gradually attracts our attention. The traditional design methods cannot assure the security of composites structure at any instance, however, reliability-based design can make up their flaws, the latter considers the design parameters as random variables which have definite probability distributions,and using reliability theory to research the destruct probability of the laminate structures, therefore, it can reflect the security levels factually and objectivity.As the definition of uniform standards for construction structures design of our country, structure reliability includes three contents, that is, security, applicability and wear. Generally, the security, applicability and wear of structure are interactional, for example, when the wear of structure lacks, the resistance capability of structure will reduce, and cause the security of structure to drop. Although actual uniform standards and criterions for structure reliability design have included the conception of structure wear, for this special newly material-composites, we seldom consider the changes of security of laminate structures caused by wear problems in their designs. Based on the above, the work of this paper is outlined as follows:1. A time-dependent model of composite laminate intensity under the moisture environments is presented. Intensity disintegration curve of carbon fiber reinforced epoxy resin composites is given using existing experiment data.2. Basing on the primary research in the first process, we introduce the time-dependent reliability theory into the composites laminate structures, and found the time-dependent reliability analysis models combining with The Classical Laminate Theory.3. Combining the first process and the second process, analyzing the time-dependent reliability of carbon fiber reinforced epoxy resin composites. The discrete point method and the stochastic process method are used to calculate the structural reliability.